Misúrová E, Kalina I
Folia Biol (Praha). 1982;28(4):233-42.
The quantitative changes in nucleic acids, 3H-thymidine incorporation and the colony-forming capacity of haemopoietic stem cells were followed in the blood of rats during 28 days after a single exposure to 5.5 Gy of X-radiation. The concentration of nucleic acids, especially that of DNA, decreased sharply already during the first day, falling to the minimum values by day 10 after irradiation. The RNA concentration recovered by day 21 and the DNA concentration by day 28. 3H-thymidine incorporation into DNA in the blood of the irradiated animals was increased, especially at 10-14 days. From the increased incorporation of the precursor into DNA after short-term (4h) labelling in vitro and without additional stimulation we judged that at that time the DNA-synthesizing cells occurred in increased numbers in the blood of the irradiated rats. Simultaneously we examined the colony-forming capacity of the blood (CFU-S) with an attempt to contribute to the elucidation of the function of DNA-synthesizing cells. The changes in colony-forming capacity proceeded in parallel to changes in 3H-thymidine incorporation, with a maximum number of CFU-S by day 14 after irradiation. The results suggest that DNA-synthesizing cells in the blood of the irradiated rats represent circulating haemopoietic stem CFU.
在单次暴露于5.5 Gy X射线后的28天内，对大鼠血液中核酸的定量变化、3H-胸腺嘧啶核苷掺入情况以及造血干细胞的集落形成能力进行了跟踪研究。核酸浓度，尤其是DNA浓度，在第一天就急剧下降，在照射后第10天降至最低值。RNA浓度在第21天恢复，DNA浓度在第28天恢复。照射动物血液中3H-胸腺嘧啶核苷掺入DNA的量增加，尤其是在第10 - 14天。通过体外短期（4小时）标记且无额外刺激时前体掺入DNA的增加，我们判断此时照射大鼠血液中DNA合成细胞的数量增加。同时，我们检测了血液的集落形成能力（CFU-S），试图有助于阐明DNA合成细胞的功能。集落形成能力的变化与3H-胸腺嘧啶核苷掺入的变化平行，照射后第14天CFU-S数量最多。结果表明，照射大鼠血液中的DNA合成细胞代表循环造血干细胞CFU。
